The present invention relates generally to haptic feedback provided to humans when interfacing with computer systems, and more particularly to haptic sensations and computer interface devices that allow the user to provide input to computer systems and allow computer systems to provide haptic feedback to the user.
A user can interact with an environment displayed by a computer to perform functions and tasks on the computer, such as playing a game, experiencing a simulation or virtual reality environment, using a computer aided design system, operating a graphical user interface (GUI), etc. Common human-computer interface devices used for such interaction include a mouse, joystick, trackball, steering wheel, stylus, tablet, pressure-sensitive sphere, or the like, that is connected to the computer system controlling the displayed environment. Typically, the computer updates the environment in response to the user's manipulation of a physical manipulandum such as a joystick handle or mouse, and provides visual and audio feedback to the user utilizing the display screen and audio speakers. The computer senses the user's manipulation of the user manipulandum through sensors provided on the interface device that send locative signals to the computer. For example, the computer displays a cursor or other graphical object in a graphical environment, where the location of the cursor is responsive to the motion of the user manipulandum.
In some interface devices, force feedback or tactile feedback is also provided to the user, more generally known herein as “haptic feedback.” These types of interface devices can provide physical sensations which are felt by the user manipulating a user manipulandum of the interface device. One or more motors or other actuators are coupled to the joystick, mouse, or other device and are connected to the controlling computer system. In kinesthetic force feedback systems, the computer system controls forces on the movement of the joystick or mouse in conjunction and coordinated with displayed events and interactions by sending control signals or commands to the actuators. For example, the Logitech Wingman Force Feedback Mouse and the Logitech I-Feel Mouse allow a user to experience haptic sensations associated with interacting a cursor with graphical objects in a GUI or web page.
Low-cost haptic devices tend to provide tactile feedback, in which forces are transmitted to a housing or portion thereof and felt by the user, rather than kinesthetic feedback, in which forces are output directly in the degrees of freedom of motion of the interface device. For example, many currently-available gamepad controllers include a spinning motor with an eccentric mass, which outputs vibrations to the housing of the controller in coordination with events occurring in a game. In some haptic mouse devices, pins, buttons, or the housing of the mouse can be vibrated in accordance with interaction of a controlled cursor with other graphical objects, which the user feels by touching those housing areas. These tactile devices are typically less sophisticated than kinesthetic devices and therefore are much less expensive to produce.
One problem with such inexpensive haptic controllers is their limited ability to convey certain types of haptic sensations to the user. For example, most pure tactile mice are incapable of providing spring and damper sensations in the sensed degrees of freedom of the mouse. These types of devices tend to be limited in producing other spatially-based haptic sensations as well. This can limit the applicability of tactile mice to interfaces designed for kinesthetic force feedback devices. For example, many traditional interface elements, such as graphical objects in a graphical user interface, tend to be associated with spatially-based force sensations. Icons, for example, are often associated with attractive and/or repulsive forces, which apply a force on a mouse in its degrees of freedom to assist the user in cursor moving tasks. However, in a tactile mouse providing no such forces in the degrees of freedom of the mouse, such haptic sensations cannot be output. What is needed are haptic sensations to associate with graphical elements in interface tasks that are compelling and useful to a user of a tactile mouse or other tactile interface device.